1. Field of the Invention
The present invention relates to a lens-fitted photographic film package, and more particularly to a construction for securing together the components of the lens-fitted photographic film package, which facilitates disassembly of the lens-fitted photographic film package.
2. Related Art
Lens-fitted photographic film packages (hereinafter referred to as film packages) are now on the market, for example, under a trademark "Quick Snap", which are a single-use camera pre-loaded with photographic film. The film packages make it possible to take pictures whenever desired without buying or carrying an expensive and heavy camera.
The film package comprises a front cover section 1, a main body section 2, and a rear cover section 3, as shown in FIG. 7. The main body section 2 accommodates an exposed film 4 which is previously pulled out from a film container 4a and is wound in a roll. A shutter cover member 5 for mounting a taking lens 9 is fixedly attached to the front of the main body section 2. When a shutter release button 6 is depressed, an exposure mechanism including a shutter actuating lever 7 and a shutter blade 8 is released from a cocked position to expose the film 4 to light passing through the taking lens 9.
When assembling the film package, the main body section 2, in which the exposure mechanism and film winding mechanism are incorporated and the unexposed film 4 and the film container 4a are accommodated, is closed by the rear cover section 3 in a light-tight fashion. The shutter cover member 5 for mounting a taking lens 9 is fixedly attached to the front of the main body section 2. Thereafter, the front cover section 1 is fixedly attached to the front of the main body section 2.
These parts may be permanently secured to each other, for example, by ultrasonic welding. But recently, the parts have been more usually assembled by snap-in engagement with each other, because this method is advantageous in view of the cost and the efficiency of assembly.
For example, a pair of hooks 10 are formed integrally on the shutter cover member 5, and a pair of engaging portions 11 are formed on the main body section 2, so that the shutter cover member 5 can be fastened to the main body section 2 by engaging the hooks 10 with the engaging portions 11, as shown in FIG. 8. Similarly, as is shown in FIG. 9, the front cover section 1 is fastened to the main body section 2 through engagement between hooks 16 and 17 which are formed integrally on the front cover section and the main body section 2, respectively.
Engaging surfaces 10a and 11a of the hooks 10 and the engaging portions 11 are substantially perpendicular to a direction A in which the shutter cover member 5 is attached to or detached from the main body section 2. Engaging surfaces 16a and 17a of the hooks 16 and 17 are also substantially perpendicular to the direction A.
A snap-in type bottom lid 3a is formed on the rear cover section. The bottom lid 3a is pried open by a photofinisher, to remove the film container 4a containing exposed photographic film therein from the film package.
Meanwhile, for environmental protection and the recycling of industrial waste, the reuse of the film packages should be affirmatively promoted, instead of simply throwing them away after the exposed photographic films have been removed therefrom for development and printing. To recover the bodies of the used film packages, they must be disassembled and the individual parts sorted according to their materials. To disassemble the bodies, it is necessary to disengage the parts from one another.
Conveniently, this disengagement process is carried out by hand. For instance, when the shutter cover member 5 or the front cover section 1 is removed from the main body section 2, a tool, such as a stick or screw driver is inserted into a hole 12 or 15, and the hook 10 or 16 is bent by the tool in a direction transverse to the direction A, so as to separate the engaging surface 10a or 16a from the engaging surface 11a or 17a, respectively. The holes 12 and 15 originally served as holes allowing removal of the molds for forming the engaging surfaces 10a and 16a by molding.
However, according to the above-described conventional arrangements, it is necessary to move the tool first in the direction A and then in a direction transverse to the direction A, as indicated by arrows shown by chain-dotted lines in FIGS. 8 and 9. This is cumbersome and reduces the efficiency of disassembly. Furthermore, the hooks 10 and 16 are frequently broken when bent by the tool, because the hooks 10 and 16 can be bent unnecessarily far. The shutter cover member 5 with the hook 10 broken or the front cover section 1 with the hook 16 broken cannot be directly reused as a part of a new film package.
Although it is desirable to automate the disassembly process, a complicated and hence expensive mechanism would be necessary for automatically moving the tool in the above-described manner. Moreover, because the depth of insertion of the tool into the holes should be limited, such an automatic disassembly mechanism requires high accuracy in positioning the workpieces and in other operations. This further increases the cost of disassembling the film packages.